Here is a way that we are currently spitting out some HTML to our view.
foreach (var reportGroup in managedReportGroup.CustomerTags)
{ %>
<%= reportGroup.Name %>
<%
}
Is there something that I can do like this? (This won't work for me)
Action<ManagedReportGroups> handlesReportGroup = delegate(ManagedReportGroups managedReportGroup)
{
foreach (var reportGroup in managedReportGroup.CustomerTags)
{
Html.Encode(reportGroup.Name);
}
};
The reason would be to cut down on the aligator brackets and clean up my code.
Thanks,
Mike
If you move it to partial views, you will still have to do the loop inside the partial.
You could create custom Html extension methods if you were really dead-set against your first example.
Or if your main goal really is to reduce "alligator brackets" you could cut it down to two if you did it this way:
<%
foreach (var reportGroup in managedReportGroup.CustomerTags)
{
Response.Write(reportGroup.Name)
}
%>
You might also consider the Spark View Engine
Why not use PartialViews?
foreach (var reportGroup in managedReportGroup.CustomerTags)
{ %>
<% Html.RenderPartial("NamePartialView", reportGroup.Name) %>
}
Then your partial view can render the name.
This is more effective when you pass in the reportGroup to the PartialView and let the partialView then either write all the HTML or call further PartialViews each rendering at a more atomic level.
Related
The standard MVC example to draw an item with the appropriate View Template is:
Html.DisplayFor(m => m.Date)
If the Model object has a property named Date of type DateTime, this returns a string with the HTML from the Display/DateTime.ascx template.
Suppose you wanted to do the same thing, but couldn't use the strongly-typed version - you didn't know the Model's type for this View at compile time. You use the older:
Html.Display("Date");
So here's the hard part.
Suppose the Model is IEnumerable. You don't know what those objects are at compile-time, but at run-time they happen to be objects with a Date of type DateTime again, like:
public class ModelClass
{
public DateTime Date { get; set; }
}
Now suppose you want your View to iterate over those objects and render each out. If all you cared about was the value you could do this:
<%
StringBuilder sb = new StringBuilder();
foreach(object obj in (IEnumerable<object>)Model)
{
Type type = obj.GetType();
foreach(PropertyInfo prop in type.GetProperties())
{
// TODO: Draw the appropriate Display PartialView/Template instead
sb.AppendLine(prop.GetValue(obj, null).ToString());
}
}
%>
<%= sb.ToString() %>
I'm obviously taking some shortcuts to keep this example focused.
Here's the point - how do I fulfill that TODO I've written for myself? I don't just want to get the value - I want to get it nicely formatted like Html.Display("Date"). But if I just call Html.Display("Date"), it inspects the Model, which is an IEnumerable, for a property named Date, which it of course does not have. Html.Display doesn't take an object as an argument to use as the Model (like Html.Display(obj, "Date"), and all the classes and methods I can find that lie underneath appear to be internal so I can't tweak and call into them directly.
There must be some simple way to accomplish what I'm trying to do, but I can't seem to find it.
Just to make sure I'm being clear - here's an example of the code of DateTime.ascx:
<%# Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<System.DateTime>" %>
<%= Model.ToString("MM/dd/yyyy") %>
And so, ideally, the output from this View that can take any Model, but in this case a list of 3 of these ModelClass objects above, would be:
11/10/2001
11/10/2002
11/10/2003
Because the code would find the Display PartialView for DateTime and render it appropriately for each.
So - how do I fulfill the TODO?
Have a look at the template code in this excellent post from Phil Haack. It seems to come close to what you are looking for: http://haacked.com/archive/2010/05/05/asp-net-mvc-tabular-display-template.aspx
I've found one potential solution to this but I'm not in love with it; it requires using several file-based templates, meaning you can't abstract this easily into a code library for use in multiple projects.
The View:
<%
StringBuilder sb = new StringBuilder();
Type itemType = Model.GetType().GetGenericArguments()[0];
sb.AppendLine("<table>");
// Pass in the Model (IEnumerable<object>)'s generic item type as
// the Model for a PartialView that draws the header
sb.Append(Html.Partial("DisplayTableHead", itemType));
foreach(object item in (IEnumerable<object>)Model)
{
sb.Append(Html.Partial("DisplayTableRow", item));
}
sb.AppendLine("</table>");
%>
<%= sb.ToString() %>
Views/Shared/DisplayTableHead.ascx:
<%# Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<Type>" %>
<tr>
<%
foreach (PropertyInfo prop in Model.GetProperties())
{
%>
<th><%= prop.Name %></th>
<%
}
%>
</tr>
Views/Shared/DisplayTableRow.ascx:
<%# Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %>
<tr>
<%
Type modelType = Model.GetType();
foreach (PropertyInfo modelField in modelType.GetProperties())
{
%>
<td><%= Html.Display(modelField.Name) %></td>
<%
}
%>
</tr>
But I now see the major flaw in this solution, which is that Clicktricity's posted solution acknowledges details in the ModelMetadata - like whether that particular property is set for display, whether it's complex or not, etc.
I've seen plenty of examples (NerdDinner, Sanderson's Sports Store, etc.) where a view is bound to a collection of objects. The syntax in the view is usually something like this...
<%# Page... Inherits="System.Web.Mvc.ViewPage<IEnumerable<MyViewModel>>" %>
...
<% foreach (var myViewModel in Model) { %>
I've also seen plenty of examples of inserts or updates where the controller automatically binds the model parameter to the form elements in the view.
I'm looking for a mix of the two techniques where my view has form elements pertaining to a collection of myViewModels where each myViewModel has 3-4 properties. The intent is to allow the user to enter a set of these in one take.
Assuming this is possible, can anyone help me with the syntax? I can't figure out how to label the form elements to make the binding work.
This is possible through the built-in model binder, but you have to do a little bit of convention-based naming of your form objects. First, your action needs to take a collection:
[HttpPost]
public ActionResult CreateFoos(List<Foo> foos)
{
// I have a list of the foo objects that were posted
}
And then, in the view, let's say you wanted to make a form for each object:
<% for (int i = 0; i < Model.Count; i++) { %>
<%: Html.TextBoxFor(x => x[i].Property1) %>
<%: Html.TextBoxFor(x => x[i].Property2) %>
<%: Html.TextBoxFor(x => x[i].Property3) %>
<% } %>
Pay attention to how the controls are rendered in the HTML, because in your "create" view, you might want to have a javascript button that allows the user to add another record, and you'll have to increase the index for each additional control. It's not too hard, but I just wanted to warn you to pay attention to the source it actually generates.
The definitive answer is here: http://haacked.com/archive/2008/10/23/model-binding-to-a-list.aspx
You need to name each field as if it were part of an array: "PropertyName[i]"
I am getting my content from a database. How can i use partial views to show content on page using that database?
database table: Content
[Id, Content] these are 2 fields
i want to get the content from db using partial views.
How i will pass an id to a partial view and show the content in view page?
You could use Html.RenderAction:
public class MyController
{
[ChildActionOnly]
public ActionResult Foo(int id)
{
var content = GetContentFromDatabase(id);
return Content(content, MediaTypeNames.Text.Html);
}
}
And in your view include the partial:
<%= Html.RenderAction("foo", "mycontroller", new { id = 5 }) %>
Remark: RenderAction is part of the now released ASP.NET MVC 2 RTM. For ASP.NET MVC 1 you may take a look at the Futures assembly containing this extension method.
Inside your view, use the Html.RenderPartial function. There are a few different uses:
You can pass in a model to the partial view: <% Html.RenderPartial("partialName", model); %>
Or you can pass in a whole new ViewDataDictionary: <% Html.RenderPartial("partialName", viewData); %>
For the full documentation, see here.
EDIT: (Answer to comment):
I would include that data as part of you're view's model. For example, let's say in your model you have:
List<Person> People;
In your view, you want to loop through each one of these, and use a PartialView to display the details:
<% foreach( var p in Model.People){ %>
<p> <% Html.RenderPartial("personPartial", p); %> </p>
<%}%>
Now, your PartialView might look like:
<%# Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<Person>" %>
<%=Model.PersonName%>
I am aware that views should not have code in them but in a project I am working on I have a lot of logic in the views.
My home page has
<% Html.RenderPartial("SearchResults"); %>
Now in the partial view I have an aweful lot of logic like this;
<div id="RestaurantsList">
<%if (Model.restaurantsList.Count() > 0)
{
foreach (var item in Model.restaurantsList)
{ %>
<% Html.RenderPartial("SearchResult", item); %>
<%
} %>
<%
}
else
{
Html.RenderPartial("NoResults");
} %>
Now I could make the home controller return a different view based on the list being empty but I don't really want that as the Index view has a few things that I want displayed no matter if there are results or not.
The only other thing I can think of here is to encapsualte this in a helper method like Html.SearchResults. But then I would need the helper to call the renderPartial for each search result also. That doesn't seem like clean seperation of concerns.
I would still have to have the first if statement in the partial view though.
How would you best handle this?
My personal opinion is that this is okay. The logic that you've used is totally related to how the model needs to be displayed.
You just need to be aware and make sure that you're never mixing in business logic, data access logic or anything else that isn't strictly tied in to the display of the model.
I agree with Praveen Angyan's answer. The only thing I could say to extend his answer is to put some of the logic in the ViewModel.
For example in the ViewModel you could hide
Model.restaurantsList.Count() > 0
behind a method or property.
E.G.:
<%if (Model.HasResturant){...}%>
this answer has nothing to do with your question.
However, I just want to let you know that calling Html.RenderPartial() inside a loop is not efficient.
ASP.NET MVC - For loop inside RenderPartial or Outside RenderPartial
Changing it to something like below would be better.
<%if (Model.restaurantsList.Count() > 0)
{
// render the Restaurant item right away
foreach (var item in Model.restaurantsList) { %>
<div>
<%= Html.Encode(item.RestaurantName); %><br />
<%= Html.Encode(item.Address); %>
</div>
<% }
}
else
{
Html.RenderPartial("NoResults");
} %>
Praveen Angyan is correct - that's view logic and it's fine that it is where it is.
But that does not change need for tidier views.
Just wanted to share small improvement.
If we attach tiny HtmlHelper method, we can shorten view to something like this:
<div id="RestaurantsList">
<% if (Model.HasRestaurants)
Html.RenderPartialForEach("SearchResult", Model.restaurantsList);
else
Html.RenderPartial("NoResults"); %>
</div>
For some - it might not look readable and nice, but it fits for me good enough.
I have a database menu structure which I would like to add to the site.master file.
I’ve looked at other questions on StackOverflow but cannot get this to work on my website.
How do I add a User Control to the Site.Master file?
Menu.ascx
<%foreach (MainMenuSort mainMenuSort in (List<MainMenuSort>)ViewData["MainMenuSortListDisplay"])
{ %>
<li><%= Html.Encode(mainMenuSort.MainMenuId.MainMenuName)%></li>
<%foreach (SubMenuSort subMenuSort in (List<SubMenuSort>)ViewData["SubMenuSortListDisplay"])
{%>
<%if (mainMenuSort.MainMenuId.Id == subMenuSort.SubMenuId.MainMenu.Id)
{ %>
<li><%= Html.Encode(subMenuSort.SubMenuId.SubMenuName)%></li>
<%} %>
<%} %>
<%}%>
You need to use the Html.RenderPartial method in your master page.
You will need to set the MainMenuSortListDisplay and SubMenuSortListDisplay view data keys in whatever action is calling the view that uses your master page.
In your master use this
<% Html.RenderPartial("~/Views/Shared/Menu.ascx");
The path needs to be the app relative path to the control's folder. Typically these go under Shared. You can make the structure how you want below the Shared folder.
To make this technique stronger, use a strongly typed partial. In the question you would perhaps make a new class (MenuModel) with two generic collections as properties and place it in the models folder of the application. Then in the model's constructor call a method that populates the lists.
public class MenuModel
{
public IEnumerable<MainMenuSort> OuterList {get; set;}
public IEnumerable<SubMEnuSort> InnerList {get; set;}
public MenuModel()
{
VoidThatFillsTheInnerAndOuterList();
}
This will mean that you can do this in your controller
public ActionResult ShowAForm()
{
ViewData["MenuPartialData"] = new MenuModel();
return View();
}
Having set this key, your master page can use the overload of RenderPartial, like this
<% Html.RenderPartial(
"~/View/Shared/Menu.ascx",
(MenuModel)ViewData["MenuPartialData"]); %>
This assumes that your partial is strongly typed to the MenuModel class. Then in the partial you can use the model which rewrites your code slightly
<% foreach (MainMenuSort mainMenuSort in Model.OuterList) { %>
<li><%= Html.Encode(mainMenuSort.MainMenuId.MainMenuName)%></li>
<% foreach (SubMenuSort subMenuSort in Model.InnerList) {%>
<%if (mainMenuSort.MainMenuId.Id == subMenuSort.SubMenuId.MainMenu.Id)
{ %>
<li><%= Html.Encode(subMenuSort.SubMenuId.SubMenuName)%></li>
<%} %>
<%} %>
<%}%>
Hope that helps
Try something like
<% Html.RenderPartial("Menu") %>
EDIT: Corrected a typo
You could also do it as a HTMLHelper and in the MasterPage just call <%= Html.Menu() %>. Then in your HTMLHelper you have the code to get the database records and loop through them. Here is a link I found to get you started. Note my comments as there is a bug in the code example provided. I'm still having issues handling subitems of menus, I guess I need a recursive function or something??
With the help of this link. I was able to display a menu in the site.master page.